Electronic printing apparatus are known which use a supply of multi-layer tape, housed in a cassette received by the printing apparatus. The multi-layer tape comprises an image receiving layer and a backing layer secured to one another via an adhesive layer. After an image has been printed onto the image receiving layer, the backing layer can be removed allowing the receiving layer to be secured to an object using the adhesive layer. Such printing apparatus include cutting mechanisms for cutting off a portion of the tape for its use as a label after an image has been printed onto the image receiving layer. For this purpose, the cutting mechanism includes a blade for cutting through all of the layers of the multi-layer tape. In some printing apparatus, the cutting mechanism also includes a tab cut blade for cutting through only one of the layers of the multi-layer tape, either the image receiving layer or the backing layer, leaving the other layer intact. For example, in a machine made and sold by Esselte under the trade mark DYMO 6000, a tab cut blade is provided which cuts through the top image receiving layer while leaving the backing layer intact. Such a tab cut allows easy separation of the image receiving layer from the backing layer.
In the DYMO 6000, the tab cut blade is a ceramic blade which is set via insert molding in a tab cut blade holder to a protrusion of about 100 microns. When a tab cut is to be made, force is applied to the blade holder to cause the blade to cut through the image receiving layer of the tape while the tape is supported by a flat anvil surface. Precise control of the amount of blade protruding from the blade holder ensures that a reliable tab cut is made which always cuts through the image receiving layer without cutting the backing layer.
One problem with this arrangement is that it requires the application of significant force, particularly when cutting wide tapes. These printing apparatus operate with tapes having widths of 6 mm, 12 mm and 19 mm. When performing a tab cut on a 19 mm tape, the force required can be as much as 80 to 100 N. It is very difficult for smaller printing apparatus to apply the high loads that the cutting operation requires.
A cutting mechanism which overcomes this difficulty is described in our copending U.S. application Ser. No. 08/556,885. In the disclosed cutting mechanism, an anvil is mounted for rolling motion relative to a cutting blade. To perform a cut, the anvil is rolled along the blade, progressively cutting across the tape. Thus, the actuation force required in this operation is much lower than if the entire width of tape were to be cut simultaneously.
In the '885 application, in which the rolling anvil is used to implement a tab cut, a full cut is implemented by a separate cutting mechanism, mechanically connected to the rolling anvil. This separate mechanism forces the entire cutting edge of a blade against a stationary anvil at once, and hence requires a large force to be applied during the cut.
As described in U.S. Pat. No. 5,458,423, a mechanism that produces a full cut can be disabled so that only a tab cutting mechanism operates. This allows a string of labels to be produced, wherein the labels are secured to a common backing strip and separated by tab cuts. The disabling of the full cutting mechanism in this reference, however, must be done manually. From a practical point of view, this means that the machine must be located accessibly to a user.
It is desirable to provide for remote printing devices which can operate by communication with host PCs or other desktop label formulation apparatus. Such printing and cutting devices can be controlled remotely from the printing apparatus itself.